Series 60 DDEC V Troubleshooting – Section 80.1 Troubleshooting the Vehicle Interface Harness +5 Volt Supply

Section 80.1
Troubleshooting the Vehicle Interface Harness +5 Volt Supply

Referral to this section indicates a fault within the Vehicle Interface Harness (VIH). See the Figure 45698 on the previous page.‪

Note: It is suggested that the vehicle interface module be installed for test. If the fault(s) clear, you may wish to contact the vehicle manufacturer for instructions on troubleshooting. Otherwise, continue with this section.

The following procedure will troubleshoot vehicle harness.‪

Section 80.1.1
Check for Low Battery Voltage

Plug in the diagnostic tool to check for low battery voltage. If code p 168/1 is logged, refer to "49.2.1 Battery Check" . If code p 168/1 is not logged, refer to "80.1.2 Check for +5 Volts" .‪

Section 80.1.2
Check for +5 Volts

Perform the following steps to check for +5 volts at the Throttle Position Sensor/Accelerator Pedal Sensor (TPS/AP Sensor):‪

1. Turn vehicle ignition switch OFF.
2. Disconnect the TPS/AP Sensor (disconnect the VSG and PSG, if applicable).
3. Turn vehicle ignition switch ON.
4. Measure voltage on the TPS/AP Sensor harness connector, pin C (red lead) to pin A (black lead), and pin A to pin B at the PSG connector, if applicable.
   1. If the voltage measurement is between 4.7 and 5.2 volts, the voltage reading is correct. Check voltage at the next connector. If all connector voltage readings are correct, refer to "80.1.5 Vehicle Harness 5V Check TPS" .
   2. If the voltage measurement is less than 4.7 volts, refer to "80.1.3 Check for +5 Volts or Return Open" .
   3. If the voltage measurement is greater than 5.2 volts at all connectors, refer to "80.1.8 Check for Short to Battery (+)" .

Section 80.1.3
Check for +5 Volts or Return Open

Perform the following steps to check for +5 volts or return open:‪

1. Turn vehicle ignition switch OFF.
2. Disconnect the vehicle harness connector at the ECM/ECU.
3. Install a jumper wire between pins V-11 and V-60 of the TPS harness connector.
4. Measure resistance between sockets V-11 and V-60 of the vehicle harness connector.
   1. If the resistance measurement is less than or equal to 5 Ω, refer to "80.1.4 Check for +5 Short to Ground" .
   2. If the resistance measurement is greater than 5 Ω or open, either the vehicle +5 volt line (V-11) or the sensor return line (V-60) is open. Refer to "80.1.8.1 Verify Repairs" .

Section 80.1.4
Check for +5 Short to Ground

Perform the following steps to check for +5 short to ground:‪

1. Remove jumper wire.
2. Measure resistance between pins A and C of the TPS/AP Sensor harness connector.
3. Measure resistance between pin C of the TPS/AP Sensor harness connector and a good ground (battery-).
   1. If the resistance measurement for both readings is greater than 1,000 Ω, or open, refer to "80.1.7 Check ECM/ECU Connectors" .
   2. If either resistance measurement is less than or equal to 1,000 Ω, wire (V-11) is shorted to wire (V-60), or battery ground. Repair the short and refer to "80.1.8.1 Verify Repairs" .

Section 80.1.5
Vehicle Harness 5V Check TPS

Perform the following steps to check TPS/AP Sensor:‪

1. Turn vehicle ignition switch OFF.
2. Reconnect the TPS/AP Sensor connector.
3. Turn vehicle ignition switch ON.
4. Select Throttle Sensor percentage on the diagnostic tool.
5. Observe throttle percentage at both no throttle and full throttle (engine not running).
   1. If the percentage is between 0 and 100%, refer to "80.1.7 Check ECM/ECU Connectors" .
   2. If not getting a reading between 0 and 100%, refer to "80.1.6 Vehicle Harness 5V Check Throttle Position Sensor Connectors" .

Section 80.1.6
Vehicle Harness 5V Check Throttle Position Sensor Connectors

Perform the following steps to check TPS connectors.‪

1. Turn vehicle ignition switch OFF.
2. Disconnect the TPS/AP Sensor.
3. Inspect terminals at the TPS/AP Sensor connectors (sensor side and harness side) for damage; bent, corroded and unseated pins or sockets.
   1. If the terminals and connectors are not damaged, replace TPS/AP Sensor. Refer to "80.1.8.1 Verify Repairs" .
   2. If the terminals and connectors are damaged, repair them. Refer to "80.1.8.1 Verify Repairs" .

Section 80.1.7
Check ECM/ECU Connectors

Perform the following steps to check the ECM/ECU connectors.‪

1. Turn vehicle ignition switch OFF.
2. Disconnect the vehicle harness connector at the ECM/ECU (if not already disconnected).
3. Check terminals at the ECM/ECU vehicle harness connector (both the ECM/ECU and harness side) for damage; bent, corroded and unseated pins or sockets (especially terminals V-60, V-11, V-13). Install new terminal if in doubt.
   1. If the terminals and connectors are not damaged, refer to "79.1.2 Check for +5 Volts" .
   2. If the terminals and connectors are damaged, repair them. Refer to "80.1.8.1 Verify Repairs" .

Section 80.1.8
Check for Short to Battery (+)

Perform the following steps to check for a short to battery (+).‪

1. Turn vehicle ignition switch OFF.
2. Remove both fuses or circuit breakers to the ECM/ECU.
3. Disconnect the vehicle harness connectors at the ECM/ECU.
4. Measure resistance between sockets V-11 and V-15 on the vehicle harness connector.
5. Measure resistance between socket V-11 on the vehicle harness connector and the battery (+).
   1. If the resistance measurement for all readings is greater than 1,000 Ω, or open, refer to "80.1.7 Check ECM/ECU Connectors" .
   2. If the resistance measurement is less than 1,000 Ω, a short exists between the vehicle +5 volt line V-11 and the lines where less than 1,000 was read (+Battery or V-15). Repair the short and refer to "80.1.8.1 Verify Repairs" .

Section 80.1.8.1
Verify Repairs

Perform the following steps to verify repairs.‪

1. Turn vehicle ignition switch OFF.
2. Reconnect all connectors.
3. Reconnect fuses (or circuit breakers) if previously disconnected.
4. Turn ignition ON.
5. Clear codes.
6. If Amber Warning Lamp (CEL/AWL) does not stay on, start engine and run for one minute.
7. Stop engine.
8. Read inactive codes with the diagnostic tool.
   1. If no codes are logged, troubleshooting is complete.
   2. If codes that brought you to this section are still logged, all system diagnostics are complete. Review this section from the first step to find the error. Refer to "80.1.1 Check for Low Battery Voltage" .
   3. If codes except those that brought you to this section are logged, refer to "18.3 First Step for Diagnosing a Fault Within the DDEC System" .